Thousands of individuals each year suffer a stroke affecting the left hemisphere of the brain and develop aphasia, an acquired language disability. One of the most common symptoms of aphasia is word retrieval impairment, which can disrupt the ability to express even basic thoughts and needs. Several behavioral treatment methods have been described that have positive impact on word retrieval abilities, largely in constrained picture naming tasks. The true impact of treatment gains need to be appreciated as well during conversational word retrieval, that is, at the level of communication activities/participation (WHO, 2001). Much less evidence is available about the most effective treatments leading to positive outcomes in discourse level- communication. Further, word retrieval treatment studies have often shown largest treatment effects in individuals with mild-to-moderate impairments, often characterized by failure in lexical phonologic stages of word retrieval, and more limited effects in individuals with severe semantically-based word retrieval impairments. That is, those with the greatest needs to communicate, if only with single words, have the poorest response to word retrieval treatment. The purpose of this project is to investigate modified versions of two word retrieval treatment approaches, errorless naming treatment and verbal+gestural treatment, for their effects not only for picture naming, but also for measures of communication activities/participation. Further, we will examine treatment outcomes in individuals with phonologic and semantic word retrieval impairments. Because our treatments are still in exploratory stages of development, we plan to test 16 participants, 8 in each treatment protocol, using single participant multiple baseline experimental designs replicated across word sets and participants. Half of the participants receiving each treatment will have semantically-based impairments. We will examine the effects of our treatments for word retrieval and gesture production in picture naming and discourse samples, as well as in communication rating scales measured at treatment completion and at one month follow up. Finally, we will compare outcomes for picture naming probes administered daily versus those administered at pre- and post- treatment to determine any impact of this errorful research design for errorless training. PUBLIC HEALTH RELEVANCE: Hundreds of thousands of individuals are living with the consequences of stroke, including aphasia, an impairment in the ability to understand and express oneself through words and sentences. This project aims to identify more effective methods of speech therapy to assist individuals who are recovering from stroke and aphasia to maximize their ability to express ideas and basic needs during daily life activities.